Dinomite.net

If you try to rsync from a Mac OS X machine using the -E switch (capture extended attributes & resource forks - you want this) to a Linux or BSD computer, you’ll get something like the following error:

rsync: on remote machine: -vlogDtprzE: unknown option
rsync error: syntax or usage error (code 1) at main.c(1108)
rsync: connection unexpectedly closed (0 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at /SourceCache/rsync/rsync-30/rsync/io.c(359)

What’s the holdup? Well, resource forks are a purely Mac OS construct (though NTFS has Alternative Data Streams that aren’t often used) allowing specific data, such as icons and application metadata, to be shoved into a file. The standard version of rsync doesn’t support these containers, so Apple includes a patched version in Mac OS X to handle them and in order to get this support on a non-Mac, you must install this patched version. Doing so is a fairly simple affair, since Apple makes the patch readily available through their Darwin source site.

Since I’m running Mac OS 10.5.2 (the latest update to Leopard), the files I need are in the 10.5.2 branch of the darwinsource directory; change that number to your version of OS X or navigate from the above mentioned Darwin source site.

wget http://www.opensource.apple.com/darwinsource/10.5.2/rsync-30/rsync-2.6.3.tar.gz \
http://www.opensource.apple.com/darwinsource/10.5.2/rsync-30/patches/EA.diff

Don’t ask me why the directory is rsync-30 when they’re using rsync-2.6.3. Now it’s just a simple matter of unpacking the source, applying the patch and compiling rsync:

tar zxf rsync-2.6.3.tar.gz && cd rsync-2.6.3 && patch < ../EA.diff && \
./configure --enable-ea-support && make && sudo make install

By default, it installs to /usr/local/bin/rsync so installing this version won’t trash that put in place by your sytem’s package manager. I also found a post on macosxhints.com concerning rsync interacting with the disk indexing of Spotlight. If you are writing tons of files to a Spotlight-indexed disk on a Mac, the indexer can become overwhelmed. The solution is to disable Spotlight on the disk in question with mdutil -i off <mountpoint> or to write into a directory appended with .noindex.